McCormack should be back in the Villa squad for Saturday's clash with Wigan Athletic, but Baker and backup goalkeeper Mark Bunn are expected to miss out.
Rushian Hepburn-Murphy's first-half strike failed to prevent Kevin MacDonald's side from falling to a 2-1 defeat at Villa Park on Monday night.
The 18-year-old summer signing from Anderlecht produced an impressive display for the Under-21s in Monday night's 1-0 win over Wolverhampton Wanderers.
Aston Villa have signed young goalkeeper Matija Sarkic from Anderlecht.
Anderlecht youngster Matija Sarkic is reportedly on the radar of Premier League outfit West Ham United.